Orr was or­dained an Amer­i­can Bap­tist min­is­ter in 1940, at­tend­ed North­west­ern Un­i­ver­si­ty (MA 1941) and North­ern Bap­tist Sem­in­ary (ThD 1943), and served as a chap­lain in the U.S. Air Force in the Pa­ci­fic in World War II. Af­ter the war, he con­tin­ued his school­ing, at­tend­ing Ox­ford Un­i­ver­si­ty (PhD 1948) and the Un­i­ver­si­ty of Cal­i­for­nia at Los An­ge­les (EdD 1971); he al­so re­ceived hon­o­rary de­grees from an In­di­an sem­in­ary and the Un­i­ver­si­ty of South Afr­i­ca. In 1967 he be­came a pro­fess­or in the School of World Mis­sions at Ful­ler The­o­lo­gic­al Sem­in­ary, Pa­sa­de­na, Cal­i­forn­ia. He wrote at least six hymns, and a number of books, in­clud­ing: